Range finder



June 4, 1946. MIHALYI 2,401,?2

' RANGE FINDER Filed Jan. 19, 1943 'z sheets-sheeu JOSEPH MIHALYI INVENTOR ATT'Y & AG'T June 4-, 1946.

J. MIHALYI RANGE FINDER Filed Jan. 19, 1943 2 Sheets-Sheet 2 w mm A M & m .Y M w H A P E Patented-June 4, 1946 I STATES I 2,401,702 RANGE FINDER Joseph Mihalyi, Rochester, N. Y., assignor to Easte man Kodak Company; Rochester; N. Y., .a-corporation of New Jersey Application January 19, 1943, SerialNo; 472,833

Title gg? 1 riled Inventors lviotmftsifor optical ele- 461, 584

J an. Jan.

Jan.

Jan.

Mar. 13, Mar. Mar. Mar. Mar. Mar. Mar. Apr. 1,1943

Do.. Mihalyi, MacNeille. Mihalyi, Tuttle. 43 Mihalyi.

Do. Holmes, Mihalyi. Mihalyi, MecNeille. MaoNeille, Holmes. Mihalyi, MacNeille. Mihalyi. MaeNeille.

MacNeille.

MacNeille, Mihalyi. MaeNeille MacNellle, Mihalyi.

men

Range finder construction. Rangefinders-Gase A Rangefindrs0sse B. Range finders-Case D. Rangefinders-Case Range finders-Case F Rengefindcrs -Gese G. Range -finders-0ese H. Range'finders0ase 1.. Range finders -Case 1.. Renge'flnderseCese K. Range finders-Case L Poleri'zing beam splitten. Range finders-Case M. Rangefinders-Case N. Benge findersCase -0 Range findersCase P June June June Oct.

Case A of thiszserie s relates broadly team invention-which has for its main objectthereduction or elimination of errors due to maladjustment of the optical system of a range finder. The broad invention also provided anarrangement 2 v distance or perhaps both so that the. observer is able to makethe object and .marklappear at the same distance; The setting of the rangingrad justor is,in prior systems, an indication of the range 8 According to: the present invention, a 'pair of adjustmentcoindi-cantlelements such as ascale and index on a coincidence line and fiducialmark are-positioned one in each of the image planes for viewing therange scale or. its equivalentdirectly in the eyepiece of the range finder so as to give an automaticallycorrected reading while ranging and/or an indicationthat the instrument is in proper adjustment.

The present Case C relates to an invention having similar objects and advantages specifically with reference to stereo range finders.

Stereoscopic range finders usually consist of a housing. with two spaced windows in the front thereof to constitute viewing. points and with right and left eye eyepieces for viewing correspending image planes in the housing. With each halfof the system there is associated an optical system for forming in the. image planes stereoscopic images of the object being ranged. These two images, viewed stereoscopicallythrough the or at least optically-in theimage planes. An image-of one ofthese adjustment coindicant ele'-' ments is: projected (the projected beam. passing through both theright and" left eye optica1"sys= tours) to forman-image adjacent to-the other adjustmentcoindicant element or at least adjacent to an image of the other element. Todo this auxiliary reflectors are required-near each offthe windows for receiving light homa e of the optical'systems and reflecting it to the other auxiliaryreflectonand hack into the other optical system. This beam of light for formingthe element image must pass through the light deviating'means if oneis usedor, if the ranging adjustor consists of-means fori'noving one of'the' reticle marks, the same adjustor must move one of the adjustment; eoindicant elements. In either case, the relative apparent position of the elements; is adjustedjbythe ranging adjustor.

To eliminate any error due to relative movement of.the adjustmentcoindicant elements and the reticles; eachelement. is preferably attached to the adjacent reticle mark .to' move therewith. Ofwcourse, in thecase where a movable coin; cidenceline constitutes one or the adjustment coindicant elements this attachment is not rigid. Preferably also the adjustment coindicant'elements are visible in at least one of the eyepieces. The. auxiliary, reflectors are preferably optical squares, such. as penta prisms which are small compared to the diameter. of the adjacent windows so, as not to. interfere. materially with the beamset.the'objeotbeing ranged. Inone species game-invention: to which this case is particular- 1y directed, the adjustment coinclicant: elements are a sca-le-andamindex and the image ofone, of thes elements" is projected: adjacent to the other element'iitself; V l

Otl ie'r objects and advantages of the present invention willbe fully understood from the following' descriptionwhen read in connection with the accompanyingdrawings, inwhich:

Fig: 1 is aperSpectiVe View of a stereo range finder incorporating the present invention. IA showsthvbinoculai view through the eye"- 3 pieces of this finder. Fig. 1B shows the field of view of the ranging observer.

Fig. 2 shows the binocular view through the eyepieces of an embodiment only slightly different from that shown in Fig. 1.

Fig. 3 is a perspective view of a preferred embodimentof the invention. Fig. 3A is the binocular view" thro'iigli} the eyr'jiee's' theiialFj-i rangement shown in-"Fig'. 3. *Fig.=-3B=is-"aview through the range observers eyepiece of an embodiment slightly different from that shown in .7

Fig. 6 illustrates a more complicated, and

Fig. 3.

optical system is shown in Fig. 3. i

Fig. 5 is a plan view of a slightly different embodiment employing a similar optical system.

Fig. 6 is a perspective view of an alternative embodiment of the invention.

Fig. 4is a plan view of a range finder 4 comparison fields l3. In the alternative embodiment illustrated by broken lines in Fig; 3. a prism 45 and eyepiece 46 are provided to allow an auxiliary observer whose eye is shown at 41 to read the range. The auxiliary observers field of view is shown in Fig. 33.

Fig. differs from Fig. 4 by elimination of the light -;deviating means 331and the substitution of a support 35 and driving screw 36 for" moving the reticle mark |4 together with the scale 39 integrally attached thereto.

: hence, less preferable embodiment'of the invention, but it is included since it has" certain advantages and also since it aids in distinguishing fails to have an element image adjacent to another element or image thereof.

Fig. 7 is an alternative form of one detail of eyes-i'IR'and llLofian-observer. ;The comparia soh planes are provided with;retic1e marks I4 which viewed stereoscopically give an-apparent mark distance to be'compared with the apparent object distance. These apparent distances are adjusted either by light'deviatingmeans or by moving one of the reticle marksuntil they are the same. r I

vAccording to the invention, light from. a lamp is reflected by a prism 2| past an index 22 located in the same plane as thctreticle mark M. This lightfrom the index 22 is collimated by the objective .|2 andgis reflected by'mirror II and penta-prism 24 asindicatedby ray 25 to another penta-prism :26 which in turn reflects it back into the rangefinder to -b.e,brought. to focus as indicated by theray 25 forming an image 2 2Iin the comparison plane |3rwhich also carries a scale 23. In a simple; form of the invention this index 22' may be read on thescale 23 by an aux-v iliary observer whose eye is shown at 21, and whose field of View is shown in Fig. 1B. M

In a preferredform of theinventiomhowever,

the mark 22 is replacedbya rharki'B fright in the comparison plane. |3 as indicated bestin Fig. 2. The image 28' of this markis then in-thevother comparison plane adjacent to a scale 29. In this embodiment the scale 29..and index 28f..;may .be

read by the main observer while =viewing the objectimageslS. I i f v I.

A somewhat more complicated arrangement is shown in Figs; 3; 4, and 5 wherein light rr'omith objectbeing ranged passes through the front windows 34 in the housing 3|) of the finder and is reflected by optical squa es-3| 'through'ob .iectives I2 to form the images' in 'the comparison planes I3. These imagesa're relayed by" lenses 28, erecting-prisms 32 and adjustable prisms 31 (which allow for different interpupillary separations) to the focal planes of the eyepieces IBR and ISL. The range-is,adjustedby -a-light-deviating device 33 and zero adjustment-is provided by-a suitable deviator 4|. Similarly, halving adjustment is provided by .atipping blocklll According'to the invention, light from a lamp 20 throughxa prism 2| is brought tofocusforming an image 22',adjacent to ascalefiain ang r the In Fig. 6 the main difference from Fig. 1 is that the scale 52is illuminated by a light source and a prism 5| so that a lightfrom the scale is projected through they system .in a manner similar-to that of the light from the index 2|. ,Thes two beamsare then reflected respectively by the optical squares 26 and 24 toward each other to strike prisms 53 which reflect both into alignment and upward through a lens 54 which brings the beams to focus in a focal plane 55 forming images 52' and of this element adjacent teat-least an image of but as far as the present invention is'concerned..

does not differ otherwise from Fig, 3. The com; plete optical system of a range finder having this feature is identical with Fig. 3 except for the method of viewing the scale, and hence, only'this' detail is shown in Fig. '7. The element beam approaching the reticle plane I3 is reflected up-,

ward by a reflector 6| to form an image atthe optical equivalent of the reticle plane |3. This image 22' as shown in Fig. 7A acts as the fiducial mark to indicate the proper setting'of a coincidence line 63 carried on a disk' in the image plane. In the operation of the'devicethe' auxiliary observer whose eye is shown at 41', rotates the disk 60 until the coincidence line 63 isin coincidence withthe image 22 as shown in Fig.

1 7A. Of course any suitable scale and index could be provided on the disk 60, but for convenience the scale 64 is adjacent to'the spiral coincidence line 63 so as to be readable in the field of the eye piece 46. 'An index for the scale 64 is shownas the mark 10 which may be either engraved on a disk 69 adjacent to the'disktll or may be'projected through theo'pticalsystem along with'th'e index 22. To ins'ureno relative movement of thecoincidence line63 (specifically of its centerwhich'isthe pivot'point of the: disk 60) and the reticle' mark'in the imageplane' Hi, the disk Ellis pivotally mounted 'on' an arm 62 cemented to the disk |3 andtothe pris'ni fili j Since the setting. of the halving adjuster. o

optical system forms an image H a show in Fig. 7A. For proper adjustment this image I! must fall between two mark 12 engraved on the disk 59. If the image H does not appear in this position, the halving adjustor is operated to correct this. If the mark it! is also an image, it will, of course, be brought to the correct reading when the mark 1! is properly adjusted. It is for this reason that the mark l0 may be either projected through the optical system or engraved on the disk 69 to act as an index to the scale 6 This feature of the invention is discussed in detail in Case E of this series.

Having thus described various embodiments of my invention, I wish to point out that it is not limited to these structures, but is of the scope of the appended claims.

I claim:

1. A stereoscopic range finder comprising a housing with two spaced windows in the front thereof, right and left eye eye-pieces for viewing corresponding image planes in the housing, an optical system associated with each window for forming in said image planes, stereo separation images of the object being ranged, the two images fusing stereoscopically to give an apparent object distance, a reticle mark at least optically in each plane fusing stereoscopically to give an apparent mark distance and a ranging adjuster for adjusting said apparent distances relative to one cluding both optical systems and reflectors near the windows for reflecting light from one system into the other, for receiving light from at least one of the elements and for focusing adjacent to at least an image of the other element, an image of said one element, the relative apparent position of the elements being also adjusted by the ranging adjuster.

2. A range finder according to claim 1 in which each element is attached directly to the adjacent reticle mark to move therewith.

3. A range finder according to claim 1 in which the ranging adjuster comprises means for moving one reticle mark and one element laterally.

4. A range finder according to claim 1 in which the ranging adjuster comprises light deviating means in the path of both the element image forming beam and one of the object image forming beams.

5. A range finder according to claim 1 in which said one element and said other element image are viewable through one of the eyepieces.

6. A range finder according to claim 1 in which the reflectors are optical squares which are small compared to the diameters of the adjacent windows.

'7. A range finder according to claim 1 in which said one element is viewable substantially directly and the other element image is projected adjacent to said one element itself.

8. A range finder according to claim 1 in which said elements are a scale and an index.

9. A range finder according to claim 1 in which halving adjustment indication marks are included adjacent to the elements and said marks are optically operated on by said light receiving and image focusing means in the same way as said elements.

10. A range finder comprising a tubular housing having two windows in the front thereof near the ends of the housing, reflectors immediately behind each window for reflecting light beams coming through the windows approximately. at right angles toward the center of the housing, reflecting devices near the center of the housing for receiving the two beams and reflecting them parallel to each other, right and left eye eyepieces respectively for receiving the parallel beams, a reticle mark in each beam at least optically at the focal plane of each eyepiece, an objective in each beam between the reticle mark and the window and at its focal length axially from the reticle mark for forming in the reticle plane an image of the object being viewed by the window, stereoscopic fusion giving apparent object and reticle mark distances, means for transversely adjusting relative to one another the object image and reticle mark in one of the reticle planes to make said apparent distances the same, said range finder being characterized by one of a pair of adjustment coindicant elements at least optically in one reticle plane, the other of said pair being adjacent to and at least optically in the other reticle plane, a reflecting surface positioned to give a virtual image of one element in said other reticle plane as viewed from the corresponding objective, means for illuminating one of the elements so that light passes, therefrom through the corresponding objective and. reflector to form a collimated beam directed at ileastapproximately toward the corresponding front windew, an optical square which is small compared to the reflector and which is near the window for receiving the collimated beam and directing it toward the other window, a second small optical square correspondingly located near said other window for redirecting the collimated beam to the other reflector and objective and into focus to form an image of said one element adjacent to the other element, means for viewing said element image and said other element at least at the point where one element coincides with the other, said adjusting means being coupled to move said element image relative to said other element.

11. A range finder according to claim 10 in which said elements are a scale and an index.

12. A range finder according to claim 10 including relay lenses between the reticle planes and the focal planes of the eyepieces for focusing in said focal planes images of the reticle marks.

13. A range finder according to claim 10 in which each objective is between its reticle plane and the corresponding reflector.

14. A range finder according to claim 10 in which the adjusting means moves the reticle mark.

15. A range finder according to claim 10 in which the adjusting means includes wedges for adjusting the object image and the element image.

16. A range finder according to claim 10 in which an index is the element which is illuminated and which is projected into focus adjacent to the other element which is a scale.

17. A range finder according to claim 10 in which the illuminated element includes a. line which is one of the elements and a line at right angles thereto whose image is similarly projected adjacent to the other element and .in which fixed marks are included adjacent to the other element for comparison with the latter line image to check whether the finder is in proper halving adjustment.

JOSEPH MIHALYI, 

